Electronic telecommunication services, e.g., e-mail, social networking websites, instant messaging, voice and video telephony, and video conferencing, can be characterized by the degree of presence provided by the service. For example, conventional e-mail provides only the most attenuated degree of presence between a writer and a reader. Tele-presence systems incorporate real-time audio, real-time/real-scale high-definition video, and multiuser software applications among participants across several locations, represent state-of-the-art in degree of presence, and offer opportunities for richer collaboration among participants.
Convergent mobile telecommunications technology, e.g., devices that support video, voice, and data communication, web browsing, software applications, along with features such as geo-location and non-communication personal digital assistant (PDA) functions are in widespread use. These devices offer the opportunity for un-tethered collaboration. Each of these types of communication can be configured for various degrees of immediacy and interactivity. For example, video communication can provide: real-time dynamic interaction between participants through the use of full duplex video teleconferencing, passive viewing of a live video stream, and passive viewing of a downloaded video file. Voice communication can be real-time full duplex voice-grade channel communication as over the public switched telephone network (PSTN), real-time half duplex communication offered by most push-to-talk (PTT) services, or voice mail. Data communication can range from simple file transfer, to single user posting on a social network web page, to e-mail, to multi-user concurrent editing of a document.